I thought mine were blown also, bad buzzing with deep bass, called the guys below in FL... they could have easily said "yeah, you need to send 'em in for repair"...I would have believed them.
Instead, the guy I talked with, Bob, was super nice, told me about the epoxy fix for the black cones. It seems that after awhile the original glue/epoxy breaks loose and then they buzz like hell. That was a couple of years ago...the epoxy fix has held and I can crank them to the max with no distortion. Even if they do need repair, I can not speak highly enough of this company...they even show you how to do the fix now! Give it a shot.
http://www.carstereohelp.com/r...r.htm
P.S. Just noticed that NY94J30 gave you the same link...well this is a confirmation...awesome company!